Ornithine carbamoyl transferases from liver of the dolphin Stenella and the shark Sphyrna zygaena were purified to homogenity and compared for some kinetic and structural properties. The two enzymes showed a specific activity of 211 and 115 respectively. With respect to molecular weight, trimeric subunit structure and Km values, they were alike and similar to enzymes from other species. Both enzymes were thermolable, but they were protected from thermal inactivation in a different way by ornithine and phosphate. The two enzymes focused, respectively, at pH 8.6 and between pH 6.4 and 8.0, the former value being appreciably higher than those of enzymes from other species.
A comparative study on liver ornithine carbamoyl transferase from a marine mammal Stenella and a elasmobranch Sphyrna zygaena.
VALENTINI, GIOVANNA;
1993-01-01
Abstract
Ornithine carbamoyl transferases from liver of the dolphin Stenella and the shark Sphyrna zygaena were purified to homogenity and compared for some kinetic and structural properties. The two enzymes showed a specific activity of 211 and 115 respectively. With respect to molecular weight, trimeric subunit structure and Km values, they were alike and similar to enzymes from other species. Both enzymes were thermolable, but they were protected from thermal inactivation in a different way by ornithine and phosphate. The two enzymes focused, respectively, at pH 8.6 and between pH 6.4 and 8.0, the former value being appreciably higher than those of enzymes from other species.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
